1. Field of the Invention
This invention relates to an improved process for manufacture of acid cheese curd in conventional dairy equipment.
2. Description of the Prior Art
Various processes for preparing cheese from chemically acidified milk are known. U.S. Pat. No. 3,620,768 (Corbin) describes the acidification of cold milk at about 32.degree. F. (0.degree. C.) to about 45.degree. F. (7.2.degree. C.) to a pH of about 5.20 to about 4.88 using a free acid such as lactic acid, phosphoric acid, citric acid, acetic acid, maleic acid, sulfuric acid, hydrochloric acid, succinic acid or the like. British Pat. No. 1,247,415 (Battelle) also describes the acidification of cold milk, and moreover states at page 3, lines 3 through 7, that: "It is well known that when milk is acidified at a temperature of about 70.degree. F. (21.degree. C.) to a pH of about 5.20 or below, it coagulates almost instantly into a granular water coagulation, totally unfit for making cheese." This disclosure is supported, generally, in "Principles of Dairy Chemistry" by Robert Jenness and Stuart Patton (John Wiley and Sons, New York, 1959) at page 310, where it is stated: " . . . the sensitivity of casein to coagulation by heat is enormously increased by decreasing the pH a few tenths of a unit below the normal value for milk."
U.S. Pat. No. 3,882,250 (Loter et al) describes acidification of vigorously agitated milk at about 59.degree. F. (15.degree. C.) to about 86.degree. F. (30.degree. C.) to a pH of about 5.00 by adding 10 to 90 percent aqueous solution of free acid such as lactic acid, phosphoric acid, citric acid, acetic acid, maleic acid, sulfuric acid, hydrochloric acid, succinic acid or the like. An acidogen and proteolytic enzyme are then mixed with the acidified milk of about 59.degree. F. (15.degree. C.) to about 86.degree. F. (30.degree. C.) and the resulting mixture allowed to stand quiescent at the same temperature for about 30 minutes to about 4 hours to form an acid cheese curd suitable for making cottage cheese, baker's cheese, quark cheese, cream cheese and Neufchatel cheese.
U.S. application Ser. No. 053,921--Loter, filed July 2, 1979, now abandoned, and its copending application, U.S. application Ser. No. 223,125, filed Jan. 7, 1981, describe copending acid salts such as sodium bisulfate, ammonium bisulfate, monosodium phosphate and sodium bitartrate are acidifiers for milk in the manufacture of acid cheese curd. The acid salts may be added directly or as an aqueous solution to vigorously agitated milk in the cheesemaking process.